Typically, electronic cameras and scanners have been expensive. The need to provide full portability in an electronic camera system drives up cost and complexity. In a typical approach for a computer hookup, as shown in U.S. Pat. No. 4,933,754, a full featured video camera is coupled to a personal computer through a framegrabber circuit board accessory to capture slide images. In a system where an electronic still camera is designed to be directly tethered to the computer, the need for many expensive components is eliminated, and complexity is reduced. For example, U.S. Pat. No. 5,402,170 describes a low cost electronic still camera tethered to a personal computer which provides image processing, storage, and display of the captured images. By relying on the computer to perform these tasks, the camera cost can be greatly reduced.
Stand-alone film scanners likewise are expensive and complex. They are also usually dedicated to a single purpose, and represent a high cost to the average consumer. For example, a color sequential scanner shown in U.S. Pat. No. 5,301,244 uses a computer to perform certain functions, such as color correction, but nonetheless represents a complex, specialized piece of equipment. This high cost for a single purpose device has minimized the utility of conventional photographic film as an image input for desktop computer systems.
When it is necessary to provide more than one magnification option in a scanner, a means of translating lenses to different positions accurately is required. If a large variation in focal lengths in the lenses exists, and it is desirable to keep the linear motion of the lenses to a minimum, a simple pivoting or circular cam mechanism is not feasible. This is due to the severe angles that occur along the faces of the cam(s) when trying to move the lenses in the shortest possible distance or with a compact rotary mechanism (usually referred to as locking angles). Space constraints also contribute to the allowable size of any chosen mechanism.
It would be desirable to merge the benefits of a relatively simple film scanning platform with efficient lens translation in order to capture images resident on a film in a simple and inexpensive manner.